[MITgcm-support] output of MITgcm_contrib/mitgcm_time

[Constantinos Evangelinos]

On Tuesday 28 October 2008 1:51:53 pm David Hebert wrote:
> Hi everyone,
>
>  Can someone tell me what the output of mitgcm_time is. An example of the
> output is below. I see from mitgcm_time.awk there are meanu, means, meanw, 
> variables  but I don't quite understand what they are.
>
>  Thanks,
>
>  David
>
>  =========================
>
>  [dhebert at home/run]$ mitgcm_time STDOUT.0000
>  40 (25.836498 8.658812 25.123938 24.020000 77.139954) (0.460500 1.870777
> 0.108758 0.000000 11.740000) (26.414190 10.836876 25.427019 24.100084
> 90.794556)

First number is the number of timesteps averaged.
Next 3 parentheses refer to cpu, system and wallclock time.
Within each parenthesis, first number is arithmetic mean, second number is 
standard deviation, third number is geometic mean, fourth number is minimum 
and fifth number is maximum.

I'm glad someone is using the "-ts" flag apart from myself. :-) I've been 
meaning to respond to your benchmarking e-mails but family trouble have kept 
me from it so far - using the -ts flag and these (and some other scripts I 
need to upload) can make life a lot easier when it comes to looking at 
wallclock time per timestep (or years per wallclock hour in inverse).

I had written these up in the README file in that directory:

A series of scripts to process the STDOUT* files of MITgcm when the
"-ts" or "-papis"/"-pcls" flags were used with genmake2.

To install place the *.awk files in a directory $HOME/awk and the rest
of the mitgcm_* files in a directory $HOME/bin and make sure the
latter is in your path.

All scripts produce the number of time series data points used for
statistics followed by:

arithmetic mean, standard deviation, geometric mean, minimum, maximum

In the case of mitgcm_time, three sets of the above statistics are
produced on one line, each within parentheses, for user time, system
time and wallclock time per timestep.

mitgcm_time:		user, system and wallclock time per timestep stats
mitgcm_mflops:		user Mflop/s per timestep stats
mitgcm_mflops_w:	wallclock Mflop/s per timestep stats
mitgcm_mflops2:		user Mflop/s per timestep stats (adjoint mode)
mitgcm_mflops_w2:	wallclock Mflop/s per timestep stats (adjoint mode)
mitgcm_ipc:		user IPC per timestep stats
mitgcm_ipc_w:		wallclock IPC per timestep stats
mitgcm_ipc2:		user IPC per timestep stats (adjoint mode)
mitgcm_ipc_w2:		wallclock IPC per timestep stats (adjoint mode)

To use

script_name STDOUT_filename 

or

script_name STDOUT_filename start firstn skip

where "start" is the timestep number assigned to the first occurence of
the Mflop/s or IPC information in the STDOUT_filename, "firstn" is the
timestep number that specifies how many of the initial timesteps are
ignored for the purpose of generating statistics and "skip" is used to
specify a period between timing or counter information that is to be
skipped because for example it contains a lot of I/O and skews the
statistics. The default values are 1, 1 and 1000000 respectively. A
careful choice of these 3 should handle most cases.

The mitgcm_mflops(_w) scripts automatically discard the very first
hardware performance counter information that precedes any timestep.

STDOUT_filename can be a file compressed with compress (.Z) or gzip
(.gz) and the script transparently handles that.

Constantinos
-- 
Dr. Constantinos Evangelinos
Department of Earth, Atmospheric and Planetary Sciences
Massachusetts Institute of Technology